In general door mirrors for vehicles, a mirror housing tiltably supporting a mirror is fixed on the door of the vehicle as projected therefrom. Nowadays, however, door mirrors of such a structure that the mirror housing itself is pivotable with respect to the mirror base are proposed and used in place of door mirrors having such a fixed mirror housing. A typical tiltable door mirror is disclosed in the Japanese Unexamined Utility Model Publication No. 61-190742, for example, as shown in FIG. 1. The disclosed door mirror has a mirror base 1 which is to be fixed on a vehicle door and on which a substantially vertical shaft 2 is fixed, and a mirror housing 3 having fixed thereon a bracket 5 on which there is installed a drive unit (not shown) for tilting a mirror body on which a mirror 4 is fixed. As shown in FIG. 2, the bracket 5 has formed integrally therewith a bearing cylindrical portion 5a which supports the shaft 2. There is disposed a compression coil spring 6 between the base of the bearing cylindrical portion 5a and a spring receiver 7 of which the outward movement from the shaft 2 is limited by a cir-clip 8 fixed on the end of the shaft 2. Also there is disposed a plurality of balls 9 between the bottom of the bracket 5 and the base of shaft 2. The balls 9 are housed in a concavity 2aformed in the base of the shaft 2, and since the bracket 5 is forced toward the base of the shaft 2 under the action of the coil spring 6, the mirror housing 3 is positioned in the normal position. When applied with a large external force, the mirror housing 3 is pivoted a predetermined angle against the force of the coil spring 6.
In the conventional tiltable door mirror of such type, the mirror housing 3 is made of a lightweight synthetic resin while the bracket 5 including the bearing cylindrical portion 5a is made of a metal, for example, aluminum die-casting, which will provide a large mechanical strength. Since both these members are mechanically coupled to each other, they will exhibit a high combined weight weight as totaled. As aforementioned, the compression coil spring 6 for forcing the bracket 5 to the base of the shaft 2 is disposed between the base of the bearing cylindrical portion 5a and the spring receiver 7, and the plurality of balls 9 is disposed between the bottom of the bracket 5 and the base of the shaft 2, in order to provice a stepwise movement of the mirror housing 3. Therefore, the support structure for the mirror housing 3 is complicated and requires a high skill of the worker who installs the door mirror to the door of a vehicle. Also, because of the support structure, the door mirror of such support structure cannot be easily installed in a short time.
The present invention has an object to overcome the above-mentioned drawbacks of the conventional tiltable door mirrors by providing a door mirror having an improved and novel mirror housing supporting structure.
The present invention has another object to provide a door mirror having a mirror housing supporting structure which consists of a reduced number of parts, is lightweight, and has a high mechanical strength.
The present invention has a still another object to provide a door mirror having a simple mirror housing supporting structure and which can be installed rapidly and easily.